The buccal cavity of the mouth is that portion of the mouth between the inside of the cheek and the teeth and gums. It has long been recognized that the buccal cavity is a convenient location for the collection of saliva from human beings. One prior example of the use of the buccal cavity as a saliva collection area can be found in Immunoradiometric Assay of Salivary Anti-C3 Antibodies, by Challacombe, Journal of Immunological Methods, (1978), pages 53-59. In the Challacombe article, saliva was collected from neonates by means of a small sterile sponge placed in the mouth between the gum and the cheek. Numerous other methods and devices for collecting saliva have been utilized throughout the years. Typically, these methods for collecting saliva have comprised placement of an absorbent pad or a wad chewable material in the mouth to absorb saliva as the material rested in the mouth or was chewed by the subject.
Recently, investigators have been attracted to methods and devices for collecting oral mucosal transudate (OMT) for the collection and measurement of various analytes which may be present in a subject. Typically the device used for such mucosal transudate collection has consisted of a cotton fiber pad that is placed between the lower gum and cheek and rubbed back and forth along the gum/teeth margin (the gingival interface) followed by analysis of the material absorbed on the cotton wool swab. An example of this type of collection of material on a cotton wool swab from along the gum/teeth margin can be found in diagnosis of Hepatitis A and B by testing saliva, J. V. Parry, et al., Journal of Medical Virology, 28:255-60 (1989).
During the collection of saliva from the mouth, and in particular, the buccal cavity, it is not uncommon for the absorbent to be placed into the buccal cavity or under the tongue and to be allowed to reside there for two or more minutes. During this period of time that saliva is being collected from the mouth, moisture is being removed from the tissue surrounding the absorbent and drawn into the pad. It is not uncommon for this loss of moisture from the tissues adjacent the pad to result in the absorbent pad beginning to adhere or stick to the tissue of the mouth thereby making removal of the absorbent pad difficult or uncomfortable. It is possible for the adhesion of the absorbent pad to the mouth tissue to be sufficiently strong that the attempt to withdraw the absorbent pad from the mouth results in separation of the pad from the handle portion of the apparatus being used to manipulate the absorbent pad. In particular, it is not uncommon that the absorbent pad will be placed in the buccal cavity, and the side of the absorbent pad which is next to the teeth and gums will become stuck to the teeth or the gum tissue. This circumstance is uncomfortable for the patient and can result in separation of the absorbent pad from the handle when removal of the saliva saturated absorbent pad from the mouth is attempted.
The present invention solves the problem of adhesion of the absorbent pad to oral tissue and at the same time provides a support structure to prevent un-wanted tearing of the absorbent away from the device handle. Further, the present invention provides investigators with a means of isolating fluid absorption from areas of the mouth from which collection is not desired. In particular, one embodiment of the present invention prevents the absorbent from contacting the gingival interface at the junction of the teeth and gums and thereby prevents collection of OMT or oral mucosal transudate.